8th Grade Syndrome
by suicunespurr
Summary: Adrien is abandoning his 8th grade syndrome, preparing himself to live a normal high school life, until he meets Marinette Dupain-Cheng, a girl in his grade who has been possessed by the spirit of creation, and want his help to save the world from Hawkmoth. Chuunibyou demo Koi ga Shitai! x Miraculous Ladybug


There is a time between childhood and adulthood that pre-teens enter an awkward phase of deciding whether to stick with the joyful imagination of childhood, or move on to the reality of adulthood. Then there are the awkward teenagers that still try to embrace childhood and all the imaginative power that comes with it.

Adrien Agreste was one such person. During his pre-teen and early teenage years, he had an alter ego: Chat Noir. Chat Noir was the reincarnation of the Destructive Deity Plagg, whom after a fearsome battle, fled to earth and inhabited Adrien's left arm until it was able to fully restore power. Their pact was sealed by a ring on his left hand, where Plagg was able to dispense some of his destructive power if ever threatened by the enemy. Adrien used this power as a part-time superhero Chat Noir, while his secret identity was Adrien Agreste, teen model for his father's fashion company.

His parents called it 8th grade syndrome, his father trying very hard to forget his youth when he suffered from these delusions. His mother thought it was adorable how attached he was to his childhood. But to keep the public unaware of Adrien's delusions, they kept him home schooled, so only the surrounding neighbors knew.

Then, during the summer before his first year of high school, a switch went off. He packed away the trench coat, night vision goggles, and baton, his weapon of choice. Any notes of his adventures, were buried at the bottom of a box along with other childish drawings. The ring was lost in the drawer of his desk, and the bandage around his arm was thrown in the trash.

It was also during this time that his mother went to Tibet to focus on her health, while his father busied himself with work. It was also during this time Adrien asked to attend public high school to enjoy high school life. His father noticed how Adrien had abandoned his 8th grade syndrome, focusing instead on his piano, fencing, Chinese, and modeling. So his father agreed, and for extra measure, secured Adrien and his bodyguard an apartment close to the high school he would be attending, far away from where people knew of his eighth grade syndrome.

* * *

Adrien finished pulling out the last of his trophies, setting it upon the shelf over his desk. Given that he was limited to the space of his apartment bedroom, he only brought with him necessities. Necessities to prove his was a normal teenage boy. Which included his fencing trophies, piano recital ribbons, a few normal books along with his school books, and magazines he stuffed under the bed.

He took the box down to living room below his bedroom to find his body guard, Gorilla, putting away some newly cleaned dishes.

"I'm done unpacking my room, do you want any help?"

The Gorilla looked up from his work and shook his head "no".

"Alright, have a good night then," Adrien retreated back up to his room, looking around at his home for the next school year.

His room was more like a loft, located in the attic area of the house. Adrien had even brought with him a ladder to go up to the rooftop balcony. And from his balcony he could see his future high school where he would begin his ordinary high school life.

Adrien headed up to the balcony to take a look. All was quiet at the school, right before the new and old students returned to campus.

 _Alright Adrien, you can do this! You aren't Chat Noir. There is no Plagg. And you are definitely not going to let anyone find out about your past tomorrow._

Adrien slapped his cheeks with his hands, hoping to knock some sense into his head. He looked around to see no one was out on the streets of Paris that night, so for old time's sake, he raised his hand in the air with palm outstretched, before tightly clenching it.

"Cataclysm!" He yelled out.

The world remained silent, unaware of the troubles of a first year boy.

He smiled to himself and was about to turn in when he notice a small hand grabbing the chimney that separated himself from the neighbors. Someone was trying to go around the Chimney to his side, a small foot sliding on the railing towards him.

Without much of a second thought, he took the hand, leading the person over to his balcony.

"You know there probably is a safer way to do that," he criticized as he led the person over, stopping when they jumped down onto his balcony.

"My yoyo wasn't working, so I had to use and alternate route."

Adrien looked at his visitor, finding a girl much shorter than him, dressed in a red dress with black spots with a black shawl, and had a red and black yoyo attacked at the hip of her dress. One of her eyes was covered by an eyepatch, and she wore ladybug earrings. Her hair was as dark as the night pulled into two pigtails tied by red ribbon. Her one eye was as blue as the day sky.

Adrien could almost say he was entranced from the moment he saw her. Until she opened her mouth again.

"Do you want to see my magic?"

 _Nope, nope, nope, nope, nope. This can't be happening._ Before Adrien could internally panic further, the girl looked down the row of apartments, as if hearing a cry for help. She dashed over to the chimney opposite of Adrien's balcony and started to climb up on the railing.

"Hey, just go over the chimney," Adrien pulled her off the railing, "You could get hurt going that way." The girl looked between the railing and the chimney, finally noticing a part of the brick that stood out from the rest, allowing a perfect climb over.

"Right." The girl climbed over the chimney, the skirt of her dress puffing out as she went, Adrien looking away until she stood up on the platform.

"Bug out," she saluted then jumped over, Adrien watched until she disappeared.

Adrien fell to his knees. _No! NONONONONONO! Why? Out of all the rotten luck to live next door to someone with 8th grade syndrome._

Adrien was about bang his head against the brick wall, when he remembered he still modeled for his father's company and he had school tomorrow, and showing up with a bandage on his forehead would definitely eliminate the chance of a normal high school life.

Instead he peaked over the chimney to see a string of star shaped lights around the balcony railing, with potted plants hanging over the side. A deck chair occupied the side beside the chimney next to her skylight. Based on the recently dimmed candles on the side table, he guessed she had been summoning a spirit she was contracted to for guidance before going on her quest.

 _NO! Nononononoonono! What am I thinking. I am not getting involved with 8th grade syndrome._ Adrien marched down to his room and began to get ready for bed.

 _You came out here to get away from it, and that's what you are going to do. Besides, she may still be in junior high. So you don't have to worry. You won't see her tomorrow, and she won't ruin your normal high school life._

Adrien turned off the light with that happy thought in mind, only to be interrupted by a thump and pitter-patter of feet across his balcony.

He could deal, he could live with a junior higher suffering from 8th grade syndrome living next door.

 _Everything is going to be fine._

* * *

Adrien woke up early in the morning to make sure he had enough time in the morning to get ready, sporting the latest style of Gabriel Agreste, looking like a normal high school boy. Well, more like a wealthy normal high school boy. Surprisingly enough, Gorilla was already making breakfast by the time Adrien made it downstairs.

After breakfast, Adrien was about to leave for school when he noticed Gorilla standing behind him.

"I can walk to school by myself," Adrien insisted, Gorilla giving a quizzical look. Gorilla had been Adrien's bodyguard long before and during his 8th grade syndrome, and had kept him in line when in public. To Chat Noir, Gorilla was the silent sidekick. To Adrien, it was going to being an embarrassment being walked to high school like he was a little kid.

"Please," Adrien was ready to beg at this point. Gorilla nodded, taking off his shoes before handing Adrien his lunch.

"Thanks, I'll see you after school," Adrien ran out the door and down to the front of their apartment, stopping short before opening the door. He could see outside kids starting to walk into the school.

 _You got this Agreste. Just act casual._ Adrien opened the door, with his calm model worthy smile, and stepped out into the street. He made it all the way to the corner crosswalk without attracting any unwanted attention. He looked around, seeing no one around, he pulled out a small mirror to check his hair had been gelled to the perfect side sweep the stylists had taught him. He glanced to his side to find a girl with long brown hair and olive green eyes adjusting her bangs in her own mirror. She looked over at him, noticing his mirror. They both quickly put their mirrors away as the sign permitted them to cross.

They proceeded to walk to the school.

 _Friends, time to make friends. And she seems normal._ Adrien looked over at the girl to notice her glancing at him, before they both looked away.

"I'm Lila Rossi," the girl extended her hand, which Adrien accepted (Not too eagerly, didn't want to seem desperate).

"Adrien Agreste. What year are you?"  
"First year."

"Same, maybe we'll have some classes together."

"Maybe, that'll be at least one familiar face." Lila looked up at the first lockers before heading down another aisle.

"My locker's this way," she pointed before leaving.

"Ok, see you," Adrien walked over to his own, as calm and collected as one could be for already making a friend.

 _So far, so good, no unusual students still suffering from 8th grade syndrome._

Adrien made his way out of the locker room and to homeroom, as designated by the schedule. He found a boy sitting alone in the front listening to music while the students came in.

"Is anyone sitting here?" Adrien asked. The boy took off his head phones.

"No, help yourself bro."

Adrien sat down pulling out his school tablet. As he looked back up, he noticed Lila enter the class, giving him a shy wave before sitting down across from him, and began striking up conversation with the girls around her.

"You know Lila?" Adrien turned around to his seat partner.

"I met her on the way over here."

"Dude, she already on the circulation for being one of the prettiest girls in our school, topping even some of the seniors," answered his seat partner. Adrien looked back over to Lila, who was laughing at something one of the girls beside her said.

Friends with one of the prettiest girls in the school. This topped anything a normal highschool boy could want.

"No skating in the halls!" Adrien and his seat partner turned to look out of their class windows to see a blur of black and pink speed by before stopping at their class.

Adrien hastily held up his tablet once he recognized who was also in his class.

It was the 8th grade syndrome Ladybug from last night.

 _This can't be happening. This can't be happening._ He panicked as he glanced over at her, the girl making her way to the desk behind his. She was no longer dress like a ladybug, sporting instead pink capris, a white floral shirt and black blazer, but she still wore the red ribbons, the eye patch, the ladybug earrings, and yoyo. She eyed everyone suspiciously before settling down in her seat.

"You know her?" his seat partner asked.

"Nope. never seen her, never met her before in my life." His seat partner looked like he didn't buy, but ignored it.

"That's Marinette Dupain-Cheng. Her family owns the bakery across from school."  
"Does she always wear the eye patch?"

"Yeah, something about a reincarnation deity trapped in her eye. She's been going on about this since she early middle school."

Adrien's panic set in even further. _Reincarnation deity. Oh why did she have to be in this class, this is going to be an embarrassment, she probably is going to find out about Chat Noir, and then I'll never have a normal highschool life._

"I'm Nino by the way," his seat partner extended his hand.

"Adrien," Adrien forced a smile, burying his internal panic. A normal guy friend. That was a part of normal high school living.

* * *

So far, the day passed off very normal. He managed to take attendance like a normal person, and not doodle while the teacher went over the student handbook.

"Those of you who have P.E., Mr. D'Argencourt is expecting you at the stadium. The rest of you can head over to the library," announced the teacher as the first bell rang. Adrien glanced at his schedule to see he had study hall next due to fencing practice in the afternoon.

"Dang you got study hall?" Adrien looked up to see Nino looking over his shoulder as they left the classroom.

"Yeah, I have fencing after school."

"Cool, what do have after study hall?"

They compared schedules to see they shared the same classes with the exception of P.E.

"I'll see you after gym then," Nino head down the stairs, while Adrien headed up to the library.

"Kim!" Adrien looked around to see a tall boy attempting to chase after another boy, who nimbly made his way down the stairs to join the rest of the kids heading towards P.E. The tall boy proceeded up to the library, passing Adrien as he went.

Adrien's eyes followed after him until her noticed someone staring after the tall boy. It was Marinette. When their eyes met, Marinette ducked behind the wall. Adrien rolled his eyes. It was just 8th grade syndrome being 8th grade syndrome.

Adrien chose a corner of the room to isolate himself in once he saw Marinette walk in. He quickly pulled out a book to seem busy, but Marinette's sights were set on someone else.

She marched down his aisle and headed towards some study tables.

 _You don't care. You're not curious. Whatever she does is her own problem._

"Ivan, the deity within me is telling me you are troubled."

 _Oh come on, how cheesy could you get. Ivan yelling Kim's name would give any indication he was troubled._

"I don't know what you're talking about."

"There is a darkness in you, and if you let it consume you, the Akuma will overtake you and turn you to the darkness forever."

Adrien stifled a laugh. This girl was nuts. Worse than he ever was. Right?

Ivan snorted at Marinette's claim.

"You doubt my power?"  
"I doubt an Akuma is going to overtake me."

"Just you watch Ivan, I'll save you from the Akuma." Marinette ran out of the library.

"No running in the Library," the librarian called out.

A part of Adrien's 8th grade self wanted to see what happened next. What was an Akuma and how would it possess Ivan. But he looked around, seeing no one going after her, he remained in place. It wasn't his job to meddle with Ivan, and it was definitely not his job to follow around Marinette Dupain-Cheng.

* * *

Adrien left the library towards his next class when he ran into Nino talking to Kim.

"Dude she almost kicked your butt," Nino laughed.

"I wasn't exactly prepared to be roped in by a yoyo," Kim defended.

"Hey Adrien, you totally missed it!" Nino hailed Adrien over, Adrien having a fairly good idea who Nino was talking about.

"Marinette came running over to the gym, lassoing Kim with her yoyo. She went all full berserk on him, taking off her eye patch and everything, it was hilarious."

"It wasn't that funny. Ivan needs to learn to man up and deal with his own girl problems," Kim retorted.

"Girl problems," Adrien looked between Nino and Kim as Nino took a seat, Adrien sitting beside him.

"Ivan has a crush on Mylene," Kim nodded towards a colorful haired girl who walked in with Lila and some other girls, "But is too chicken to do anything."

"That is for Ivan to decide not you," the boy turned to the speaker to find Marinette, yoyo-less. Marinette took a seat behind Adrien, scowling at Kim. Kim held his hands up in defense and went to his own seat.

"I thought you got sent to the infirmary," asked Nino.

"The healer had enough power to repair my physical form, my magic will take some time to recuperate," she answered before pulling out her tablet, "I need to get back Miraculous Ladybug Prototype Mark III before the Akuma will attack Ivan again. The authorities of this camp have confiscated it."

"Maybe if you didn't attack people with it, they wouldn't confiscate it," scolded Adrien.

"As the embodiment of creation, Tikki has tasked me with protecting the world from the Akumas. I need my Miraculous Ladybug Prototype Mark III in order to protect Ivan."

"No you don't because Ivan is not in danger, and there no Akuma coming for him because Akumas don't exist."

Marinette was about to saying something when the teacher entered the classroom. She pouted and put her head on her desk, Adrien turning around to face the board. Nino looked back and forth between the two before shrugging.

* * *

Adrien purposely decided against going on his roof that night. He already made the mistake of talking to Marinette during school, even if it was to scold her. After that, she had kept a watch on him closely. Well, him and Ivan. And Mylene. Whatever happened during her fight with Kim, seemed to have given her the answers regarding Ivan and Mylene. So now Marinette had watched all three of them like a hawk, up until she received her yoyo with the promise not to use it on people, then she disappeared.

Adrien sat at his desk, trying to focus on his Chinese when he heard a thump on his roof. He waited for the pitter patter of feet to scurry across but found nothing.

"Chat Noir!"

Adrien jumped in his seat, causing him to fall back and hit the floor. He looked up to see Marinette poking her head through his skylight.

 _Should have locked it._

"What do you want?"

Marinette's eye lit up.

"You are Chat Noir!"  
"No I'm not. I don't know anyone by that name." Adrien scrambled to get up while Marinette dropped down, dressed in her Ladybug attire.

She reach for the sky with her palm outstretched, then clenched it.

"Cataclysm!" She shouted, Adrien quickly covering her mouth.

 _This is bad. This is really really REALLY bad._

Adrien prayed to high heaven Gorilla didn't hear her, and finally breathed when no one came up.

"Don't you ever do that again."

"Why not? You're Chat Noir, aren't you?"  
"Not anymore."

Marinette furrowed her eyes in concentration, then opened them, "you're undercover!"  
"No! I'm done, Chat Noir is long gone."

"Did you retire?"

"Chat Noir retired. I'm normal teenage boy, Adrien Agreste."

Marinette pouted and sat on the floor, Adrien remained standing.

"Can you please go Marinette? I have homework I need to do."

"I'm not Marinette. I'm Ladybug, the chosen vessel of Tikki, goddess of creation, bound by contract to be her chosen warrior until she can take her place in the heavens."

Adrien rolled his eyes as he sat down on the floor, her title similar to the one he used as Chat Noir, although his was more gruesome and depressing.

"Well, Ladybug, can you please get out of my room."

"Not until I show you."

"Show me what?"  
"That Akumas exist," Marinette pulled a bag around, also ladybug themed. She reached a hand inside and pulled out a jar with the lid also painted like a ladybug. Inside the jar was a moth.

"That's an Akuma?"

Marinette nodded, eyes full of seriousness, "It's being purified. I should be able to release it soon."

This was the first time anyone had brought him a moth in a jar before, so despite all rational of not to play along, he asked, "What do Akumas do?"

Marinette smiled, which he immediately regretted asking, despite her having a cute smile.

"Akumas are servants of the Dark Lord Hawkmoth. In a person's darkest hour, an Akuma can overcome a person and possess them. Tikki has charged me with capturing and purifying the Akuma."

Adrien nodded out of politeness, whatever she was saying going over his head. But Adrien also ducked to make sure he would not understand it, no matter how much his 8th grade self wanted to.

"It's ready," Marinette jumped up and headed towards his skylight, while Adrien sat watching her go, hoping this would be the end of her visit.

"Come on," Marinette gestured for him to follow. Adrien reluctantly followed, why he didn't know.

Once they made it to his roof, Marinette unscrewed the lid, and tilted it so the moth fell on Adrien's chimney.

"Bye bye little butterfly." The moth just sat there.

"Miraculous Ladybug!" Marinette tossed her yoyo in the air, landing with a thunk on Adrien's head. Marinette quickly put away her jar and ran to her chimney, climbing on top of it.

"Bug Out!" She jumped down to her side, Adrien leaving her to rub his head where her yoyo accidentally hit. He looked over at the moth, then scoffed.

Like the moth could do anything to help with Ivan's problems.

* * *

"Hey bro," Nino came up beside Adrien the next morning, all smiles as usual.

"Hey Nino."

"So, quick question," Nino pulled out a notebook, "the guys in our grade are doing a rating on the hottest girls in our year. Anyone you want to vote for?"

Adrien's mind immediately went to Lila, he quickly shook his thought out of his head.

"Alright, I'll get back to you, although you can't vote for Mylene anymore."  
"Why not?"

"Did you hear? She and Ivan got together. Ivan apparently sent her some poem. They're going out on their first date Friday according to Ivan." Adrien shut his locker, following Nino out of the locker hall.

"So he's not mad at Kim anymore?"

"No, if anything Kim is bragging about he got them together."

Adrien laughed as they made their way to class, finding Ivan and Mylene talking together, while Lila and the other girls crowded around.

Kim was bragging to anyone who would listen about how he got them together.

Maybe Ladybug purifying the Akuma really did help them get together.

"No skating in the halls!" Adrien turned to see a blur of pink and black pass by the window, Marinette successfully making the turn to skate into their room on her wheelies.

 _Naw, its just 8th grade syndrome. Moths don't have any power over emotions or love lives._

Adrien busied himself with his school work, barely glancing at Marinette as she passed by with a smug grin on her face once she saw Ivan and Mylene. She made herself comfortable in her seat, pushing the other girls out of the way back to their own seats.

Their homeroom teacher entered the classroom, Adrien pulling up his tablet when he could feel someone very close behind him.

"Told ya so."

* * *

 **Finished the anime _Chuunibyou demo Koi ga Shitai!_ over the weekend (including season 2, and the specials). So adorable and the main two characters reminded me of Marinette and Adrien. And since my crossover list is complete, here's the crossover. Don't know if I'll do more or not because still working on KPMLB. I just really want to write this one.**


End file.
